Washing machine for milk cans



Jan. 30, 1934. J, P. YMCKINLEY 1,945,059-

WASHING MACHINE FOR MILK CANS Filed May 16, 1932 2 Sheets-Sheet 2 Jan.30, J. p MCK|NLEY WASHING MACHINE FOR MILK CAN'S Filed May 16, 1932 2Sheets-Sheet l Patented Jan. 39, 1934 UNITED STATES FATE FFlCE 11Claims.

This invention relates to washing machines for milk cans and the like,and particularly to the handling of the cans and the inverting of thesame during the washing operation.

a An object of the invention is to provide an improved washing machinefor milk cans or similar articles, and particularly to improve andsimplify the mechanism for upending or inverting the cans after washingso that the covers may be placed thereon.

Another object of the invention is to provide improved means forinverting or upending cans as the cans are being conveyed along aprescribed course; which will handle the cans and invert them with aminimum of noise and with a minimum of inertia or momentum in the cansas they are discharged; which will upend or invert the cans insynchronized relation to the means for conveying the cans thereto andtherefrom; which will be exceptionally quiet and rapid in operation, andsimple, compact and inexpensive.

Various other objects and advantages will be apparent from the followingdescription of an embodiment of the invention, and the novel featureswill be particularly pointed out hereinafter in connection with theappended claims.

In the accompanying drawings:

Fig. 1 is a side elevation of one end of a milk can washing machine,having associated therewith a can upending or inverting mechanismconstructed in accordance with this invention;

Fig. 2 is a similar elevation of the can upending mechanism, but withthe parts in different operative positions;

Fig. 3 is a sectional plan of the cradle of the upending mechanism, thesection being taken approximately along line 33 of Fig. 1;

Fig. 4 is a diagrammatic side elevation of the cradle and its operatingmechanism, illustrating the cradle in can discharging position, and withcertain parts removed or broken better to show other details ofconstruction;

Fig. 5 is a sectional elevation of the crank and connecting rodmechanism for operating the cradle, the section being takenapproximately along the line 5-5, Fig. 2, but when the cradle is in aslightly different position;

6 is an elevation similar to Fig. 1, but from 50 the opposite side ofthe machine;

Fig. 7 is a transverse, sectional elevation of the same, with thesection taken approximately along line 7-7 of Fig. 6; and

Fig. 8 is an elevation of the cradle and its oscil- 55 lating mechanismillustrating the movement of the crank and connecting rod while thecradle remains temporarily in can receiving position.

In the illustrated embodiment of the invention, the milk cans A, whichare to be washed, are conveyed through a suitable housing 10 bypropelling them along a guide or track 11 in the housing in any suitablemanner, such as by dogs or pawls 12 which engage the cans and push themstep by step along the track 11 in the housing. The cans are conveyed inthis manner in a definite path through the housing 10 while in aninverted position, so that jets or streams of cleansing, rinsing anddrying fluids may be directed into the same in succession and drainedimmediately. The covers 13 are similarly conveyed through the upper partof the housing by pawls or dogs 14, but the covers are rolled on edgealong the guide or track 15 and when discharged, roll down an inclinedtrack 16 to a point where they are stopped by a suitable gate1'7, andheld by the latter usually until the corresponding can arrives in aposition to receive the cover.

The can upending mechanism for receiving and inverting the washed cansthat are discharged from the track or guide 11, is mounted upon asuitable base or frame 18, and includes a cradle 19 which is pivoted bypins 20 in suitable bearings 21 provided on upstanding brackets 22 atopposite sides of the frame 18. The cradle has a relatively broad, canreceiving and supporting platform or base 23 at one end which, when thecradle is in the position shown in Fig. 1, is disposed in proximity to,or slightly below, the track 11 at the discharge end of the housing 10,so that as the cans are discharged from the housing 10 by horizontalmovement of the cans, they will be received upon the base 23 of thecradle. The base 23 may be slightly inclined, as shown in Fig. 1, sothat the can will tip by gravity into an inclined position and lie alongthe cradle, as shown in Fig. 1. When the cradle is rotated about theaxis of the pins 20, such as into the position shown in Fig. 4, the canwill be inverted or upended.

During the upending, the can is held against sliding out of the cradleby a lip 24 at the end of the cradle opposite to the base 23, but as thecan closely approaches its upright position, as shown in Fig. 4, it willtip by gravity slightly and descend upon the track 25 of the frame orbase 18 of the upending mechanism. The lip 24 may move downward ythrough an opening or slot in the track 25 of the base or frame 18 andallow the can to rest fully upon the track 25. The can is positivelypropelled along the track 25 out of the path of the cradle, while thecradle is returning to can receiving position by means of areciprocating carriage 26 mounted to move along the track 25 andcarrying a pawl 27 which engages with the depending flange at the baseof the upright can, and pushes it along the track 25 and out of the pathof the returning cradle.

The cans are propelled through the housing 10, upended in the cradle 19,and then moved along the track 25 by power from any suitable source. Theillustrated example of this source is an electric motor 28, Fig. 1,which, through a belt 29, drives a shaft 30, and this shaft through agear box 31 drives a shaft 32, Fig. 6, which extends crosswise of thebase 18. At the opposite side of the washer from the gear box 31, theshaft 32. carries a pinion 33 which meshes with and drives a gear 34which is mounted ona shaft 35 that also extends crosswise of the frameor base 18, and isrotatably supported by suitable bearings thereon.

The gear 34 carries a cam 36 having an eccentrio cam groove 37, Figs. 6'and '7, in a face thereof. Anv arm 38, Figs. 2'and 6, is pivoted on ashaft 39 which extends crosswise of the frame 18; A cam follower orroller 40 on the free end of the arm 38 runs in the; cam; groove 37, andsince the cam groove is eccentric to the shaft 35, the rotation of the.gear 34 and the cam 36 will cause an oscillation of the arm 38- andthrough it of the shaft 39. An arm 41:, Figs. 1, 3, 6- and '7, is fixedon the shaft. 39 intermediate the sides of the frame or base 18, Fig."I, and is pivotally connected at its upperend to one. end of the link42, and the latter at its other or; opposite end is pivotally connectedby a pin: 43to an, arm 44 which is in turn pivoted onthe bearing stud orshaft 45 of the frame 18.

The arm 44, at its upper and free end, is pivoted by a pin46to one endof a link 47, and the latter at its opposite end is pivoted by a pin 48'to the carriage 26. which carries the pawl 27 and moves the can awayfrom the cradle. The carriage 26 is suitably mounted for reciprocationin the upper part of the frame 18, such as by having rollers 49 at. itsopposite ends which. run: in channels 50, Fig; 7,.facing one another atthe topof the frame 18. Thus, as the gear wheel 34 rotates, the carriage26 willbe-reciprocated-back and forth along the track 25.

An arm 51 is mounted on a shaft 52, Figs.v 6 and, '7', and intermediateof its ends it mounts a cam follower or roller 53 which also runs in thecam groove 37: at a point approximately opposite from the cam follower40, asshown in Fig. 6. The arm 51 is upstanding and'at its upper end ispivoted by a pin. 54 to one end of a link 55 which extends into thehousing 10,. and is therein connected to'the' mechanism whichreciprocates the pawlst12 that propel the cans through the housing bystep by step movements.

The shaft 35, on. which the gear 34 is mounted, extends across the frame18 and at the side of theframe opposite the gear 34, carriesa crank arm56. A crank pin 5'7 isprovided upon the free end of the crank arm 56,and is received within a slot 58 provided in one end of a link orconnecting rod 59. The slot 58-is elongated in shape and extends in adirection lengthwise of the link or rod 59.. The other end of the linkor rod 59 is pivoted on a stud 60 carried by an arm 61. The arm 61' isconnected to the cradle so'that rocking of the arm 61' will causerocking of the cradle, and this connection may conveniently be made 'by'fixing the arm 61 on the projecting end of oneof the bearing studs 20which mounts the cradle for oscillation. The slot 58 and pin 57 form alost motion connection between the crank arm 56 and the link 59 forgiving the cradle a short period of rest in can receiving position, aswill be explained presently.

From this foregoing description, it will be observed that through thegear wheel 34, synchronous operation will be caused of the conveyingmeans by which the cans are moved through the housing 10 of the cradlewhich rocks or oscillates to upend the cans, and of the carriage 26which removes the cans from the path of the returning cradle. Since thegear 34 is continuously rotating, the crank arm 56, which is fixed onthe same shaft, will, of course, be continuously rotating, and throughit and the link or rod- 59 the cradle will be rocked from the canreceiving position shown in Figs. 1, 6, l and 8, through theintermediate position shown in Fig. 2, and. into the can dischargingposition shown in Fig.4. The can receiving and discharging positions ofthe cradle are at the opposite dead center positions of movement of thecrank arm 56, with respect to the connecting rod or link, and hence thecradle will be approximately quiet for a short interval at each limit ofits movement while the crank arm moves through dead center positions.

Thestarting and stopping of the cradle in its movements in bothdirections will be relatively easy, because of the dead centerconnections to the crank arm, and the movement of the cradle will beaccelerated during the first half of its oscillation in each direction,and then will be gradually and increasingly checked by the same crankaction as the cradle approaches the end of its oscillation in eachdirection. A can A received in the cradle, asshown in Fig. 1, will beinverted or upended, and then discharged, as shown in Fig. 4, by theslowing up of the movement of the cradle due to the dead center actionof the crank as the cradle approaches its discharge position shown inFig. 4. This decreases the inertia of the can and prevents it from beingdischarged with material momentum. The

action is therefore especially quiet, yet rapid, and

the can will remain upright in the-position where it is discharged untilit is moved by the reciprocating carriage 26 out of the path of thereturning cradle.

As the cradle moves from the can receiving position shown in Fig. 1 tothe discharge position shown in Fig. 4, the carriage 26 will bereciprocatecl toward the housing 10, so that when the can is dischargedupon the track 25, the base of the can will be over the pawl 2'? of thecarriage 26, and the latter will engage the can at its base and move itaway from the cradle while the cradle is approximately quiet in the deadcenter position of the crank, as shown in Fig. 4. Thus the can will beremoved from the path of the.

cradle before the cradle has progressed materially in its returnmovement to receive a new can.

It is sometimes desirable to have the cradle remain stationary for ashort interval of time while in can receiving position, and the lostmotion connection provided by the pin 5'? and slot 53 makes thispossible. The can receiving position of the cradle is determined by theengagement of lugs 62 provided upon each side of the cradle and whichengage with the upright bearing brackets 22, on which the cradle ismounted, when the cradle is in the desired can receiving position, shownin Fig. 1. While the cradle may be held in this receiving position shownin Fig. 1 by the overbalancing of one end of the cradle, there is atend-v ency for the cradle to rebound when the lugs 62 hit the bearingframes 22, especially if sound absorbing means or a resilient pad isinterposed between the lugs 62 and the bearing frames 22.

To overcome this tendency, a helical spring 63 may be connected at itsends to plates 64 and 65 which fit over the projecting ends of the crankpin 57 and the stud respectively, with the spring 63 under tension.Suitable cotter pins 66 confine the plates 64 and to the pins or studson which they are mounted, and thus also confine the link 59 to thecrank pin 57 and cradle stud 60. The spring 63 urges the link 59 towardthe crank pin 57, and thus will yieldingly hold the crank pin 5'7 at theupper or inner end of the slot 58. This movement of the link 59 ispossible because the spring pulls the arm 61, and through it the cradle,sufiiciently to place the inner or upper end of the slot 58 against thecrank pin 5'7, and hence the spring acts as a resilient member which.connects the crank pin 5'7 with the cradle arm 51. When the cradlereaches its can receiving position during its returning or emptymovement, it will assume the position shown in Fig. 8 which isdetermined by the engagement of the lugs'62 with the bearing frames 22.

This engagement of the lugs 62 with the frame occurs when the crank arm56 is in the position shown by the right hand set of dash lines in Fig.8, and at that time the link 59 will also be in the position shown indash lines at the right of the full line position shown in Fig. 8. Itwill be noted at this time, when the crank arm 56 is in this right handposition shown in dash lines in Fig. 8, the crank pin 57 is s'ill at theupper or inner end of the slot 58, and the crank arm is moving in aclockwise direction in Fig. 8. Since the cradle is now held againstfurther movement in the same direction, the continued movement of thecrank arm 46 will cause the crank pin 5'7 to move along the slot 58,thereby further stretching spring 63 as the crank pin swings the linkinto the fuil line or dead center position shown in Fig. 8.

As the crank arm continues to move further in the same direction,because of its continuous rotation, the crank pin 58, after passing thedead center position, will move in the opposite direction along the slot58 until it engages the inner or upper end of the slot 58, which is theposition shown by the dash lines at the left in Fig. 8. During thismovement of the crank arm and link 59 from the full line position to thedash line posi ion at the left in Fig. 8, the spring 63 continues tohold the cradle in the can receiving position, but soon as the crank pinreengages the inner end of the slot 58, the crank pin will positivelymore the link 59 and start the oscillation of the cradle from the canreceiving position of Figs. 1, 6 and 8 into the discharge position ofig. a.

It will thus be seen that the cradle is held for a short period of timeabsolutely quite in the can receiving position, while the crankcontinues to rotate through a fraction of a revolution and past deadcenter position, which gives ample time for movement of a can from thehousing 10 into the cradle, and there is no danger of the cradle beingmoved by vibration or other sources out of proper receiving positionssince it will be held yieldingly in proper position by the spring 63 andthe lugs 62. The covers held by the gate 17 are released to fall uponthe upended can, by the upward movement of the gate 17 which is causedby the engagement of a roller 67, Fig. 2, of the gate within an inclinedcam 68 provided on the reciprocating carriage 26. The release of thecover, however, per se, forms no part of the present invention, and anysuitable cover releasing or placing mechanism may be employed, or thecovers may be placed upon the upended cans manually.

The cradle may be formed in any desired manner, but preferably I providean arcuate or partially cylindrical shell or plate 00, Figs. 1 and 3,inclined or oblique at its side edges. This plate a nestles, midway ofis ends, in the concavity of an arcuate bar or strip b which at its endsis fixed on the inner ends of the studs 20 that provide the rocking orpivotal support for the cradle. The shell'a is held to the bar or strip5 by welding, rivets or other suitable means. With this construction,the cradle may be formed largely by rolling and bending sheet metal, andyet it has the desired rigidity and strength.

The operation of this can handling mechanism should be obvious from theforegoing description of one embodiment of the invention but it will bebriefly summarized. Assuming that the mechanism is in the position shownin Fig. 1, the motor 28 is started in operation, and this will alsocause operation of an air blower B which delivers a stream of hot dryingair into the cans just before their discharge from the housing 10. Themotor also, through the shaft 30, gear box 31, and shaft 32, drives thegear 3% and the latter through the cam 36. The arm 51, and link 55,cause a step by step movement of the cans through the housing 10 wherethey are cleansed, sterilized and dried, and pushed horizontally intothe cradle, as shown in Fig. 1. crank arm 56 causes an oscillation ofthe cradle in a clockwise direction in 1 to invert or upend the can, anddischarge it when the cradle reaches the position shown in Fig. 4.

During this movement of the cradle for upending the can, the carriage 26is reciprocated by the same cam into a position to place its drivingpawl 2'? ready for engagement with the can which is upended assoon asthe can is deposited on the track 25, as shown in Fig. 4.. While thecradle is comparatively idle by reason of the dead center position ofthe crank arm 56, as shown in Fig. 4, the continued movement of the cam36 will cause the pawl 27 of the carriage 26 to move the can, throughits engagement with the bottom thereof, along the track 25 and out ofthe path of the cradle as the cradle begins its return movement toreceive a new can. The means for conveying the cans to the cradle andaway from the cradle are thus, by the arrangement described, operated inproperly timed or synchronized relation to the operation of the canupenoling mechanism, and a smooth, rapid and continuous handlihg orf thecans possible.

It will be obvious that various changes in the details which have beenherein described and illustrated in order to explain the nature of theinvention, may be made by those skilled in the art within the principleand scope of the invention, as expressed in the appended claims.

What is claimed is:-

1. In a washing machine for milk cans and the like, a track along whichinverted cans may travel, positively actuated means associated with thetrack for propelling the inverted cans step by step along said track, acan receiving cradle disposed in a position to receive a can from saidtrack, a continuously rotating member, a crank and connecting rodconnection between said-member and said cradle for oscillating thecradle about a The concomitant rotation of the 1 single axis to fullyinvert the can, and then return to can receiving position saidconnection having its dead center positions when the cradle is in canreceiving and discharging positions, means disposed to receive theinverted cans and convey them away from the cradle, and means connectingsaid rotating member and said positively actuated means for causingtheir movements in timed relation to one another, whereby said cradlewill always be in proper position to receive a can advanced along saidtrack by said propelling means and delivered to said cradle.

2. In a washing machine for milk cans and the like, means for conveyingcans in a prescribed path at specified intervals apart and by positivemovements, a cradle disposed in a position to receive the cans from saidconveying means and oscillatable about a single axis, a continuouslyrotating member, a crank pin carried by said member, link meansconnecting said cradle and crank pin, whereby rotation of said memberwill cause rocking movement of the cradle in a direction to fully invertthe can and then discharge it, said crank pin and link having their deadceni ter positions when said cradle is in can receiving or dischargingpositions, means disposed in a position to receive the discharged canfrom said cradle and convey it to another location, and means connectingsaid first conveying means and said member for causing their movementsin timed relation to one another, whereby said cradle will always be inreceiving position when a can is delivered to it.

3. in a washing machine for milk cans and the like, means for conveyingcans in a prescribed path at specified intervals apart and by positivemovements, a cradle disposed in a position to receive the cans from saidconveying means and mounted for oscillation about a single axis to fullyinvert the can and then discharge it, a rotating member, a linkpivotally connected to said cradle and member, at points materiallydistant from the axes of rotation of said cradle and member, whereby thecradle will be oscillated by the rotation of said'member sufiiciently tofully invert a can, means for receiving the inverted cans from saidcradle and conveying them to another location, and means connecting saidfirst conveying means and member for causing their movements in timedrelation to one another, whereby said cradle will always be in receivingposition when a can is delivered to it, said member and link havingtheir dead center positions when said cradle is in can receiving anddischarging positions to give the time dwell for the receipt anddischarge of the cans.

4. In a washing machine for milk cans and the like, means for conveyingcans in a prescribed path, a cradle disposed in a position to receivethe cans from said conveying means and mounted for oscillation about asingle axis to fully invert the can and then discharge it, a rotatingmember, a link pivotally connected to said cradle and membereccentrically of their axes of rotation, whereby rotation of said memberwill cause oscillation of said cradle between can-receiving andcan-discharging positions, said cradle being positioned to be in canreceiving and discharging positions at the dead center positions of saidmember and link, stop means for limiting the oscillation of said cradlebeyond said receivposition, the connection between said link and one ofsaid members being a lost motion connection, whereby when said cradlereaches canreceiving position on its return .to that position, saidrotating member may continue to move past dead center position of thelink for a limited extent without further movementof the cradle andthusprovide an interval in which the cradle is stationary while receivingthe can, and means disposed to receive the cans inverted by said cradleand discharged therefrom and to convey them to another location.

5. In awashing machine for milk cans and the like, means for conveyingthe cans in a prescribed path and discharging them, a cradle memberdisposed in a position to receive the discharged cans and mounted foroscillation about a single axis in a direction to fully invert the cansand discharge them, a rotating member, a link articulately connected atone end tosaid cradle member and its other end to said rotatingmemben'both pivotal connections being eccentrically of the axes ofrotation of said members, whereby rotation of said rotary member willcause oscillation of said crade member, said member and link having deadcenter positions while said cradle is in can receiving and dischargingpositions, the pivotal connection between said link and one of saidmembers being a pin and slot connection enabling limited relativemovement between a member and the end of the link to which it ispivotally connected at their dead centerpositions, whereby as saidcradle member approaches one limit position, the pin and slot connectionwill enable the cradle to remain stationary for a fractional portion ofthe rotation of said rotary member, and means disposed in a position toreceive an inverted can discharged by said cradle member, and to conveyit to a different location.

6.: In a washing machine for milk cans and the like, means for conveyingthe cans in a prescribed-path and. discharging them, a cradle memberdisposed in a position to receive the discharged cans and mounted foroscillation in a direction to invert the cans and discharge them, arotating member, a link articulately connected at one end to said cradlemember and its other end to said rotating member, both pivotalconnections being eccentrically of the axes of rotation of said members,whereby rotation of said rotary member will cause oscillation of saidcradle member, the pivotal'connection between said link and one of saidmembers being a pin and slot connection enabling limited relativemovement between a member and the end of the link to which .it ispivotally connected, whereby as said cradle member approaches one limitposition, the pin and slot connection will enable the cradle to remainstationary for .a fractional portion of the rotation of said rotarymember, a spring connecting the link and the pin running in said slot,and urging said pin yieldingly into one end of said slot, whereby thepin and slot connection will normally move as a unit, but may yield whensaid cradle member is stopped, a stop limiting the movement of saidcradle member in one direction as said cradle member closely approachesthe limit of its oscillation in that direction, while said pin and slotconnection permits continued movement of said member past dead centerposition, and means disposed in a position to receive an inverted candischarged by said cradle mem- 7 ber, and to convey it to a differentlocation. ing position while returning to can-receiving '7..In a washingmachine for milk cans and the like, means for conveying cans along aprescribed path, and discharging them by horizontal movement of thecans, a cradle disposed in a position to receive a can discharged bysaid conveying means, and rockably supported for oscillation in adirection to invert the can, a link pivoted at one end to said cradle ata distance from the axis of oscillation of the cradle, a rotatingmember, a crank carried by said member at a distance from the axis ofrotation of said member, said link at the other end thereof having aslot fitting over said pin with the slot running in a direction endwiseof the link, a spring connected between said link and said pin, so as tohold said pin yieldingly in one end of said slot, and means disposed ina position to receive a can inverted by the oscillation of said cradle.

8. In a washing machine for milk cans and the like, means for conveyingcans along a prescribed path, and discharging them by horizontalmovement of the cans, a cradle disposed in a position to receive a candischarged by said conveying means, and rockably supported foroscillation in a direction to invert the can, a link pivoted at one endto said cradle at a distance from the axis of oscillation of the cradle,a rotating member, a crank carried by said member at a distance from theaxis of rotation of said member, said link at the other end thereofhaving a slot fitting over said pin with the slot runnin in a directionendwise of the link, a spring urging said pin yieldingly into the end ofsaid slot nearest the end of the link which is connected to the cradle,a stop against which said cradle abuts when it reaches can-receivingposition just prior to the dead center position of said pin as itreturns the cradle to can-receiving position, whereby when said cradlereaches can-receiving position, it will be stopped and continuedmovement of said member and pin will cause said pin to move along saidslot, tension said spring and hold the cradle against return movementuntil said link passes dead center position with respect to saidrotating member, and again reaches the end of the slot into which it isurged by said spring, whereupon the cradle is started in its oscillationto invert the can, and means for receiving and conveying away the cansinverted by said cradle.

9. In a machine for washing milk cans and the like, means for conveyingsaid cans in a prescribed path and discharging them by horizontalmovement of the can, a cradle disposed in an inclined position toreceive a can when so discharged from said means, a member rotating insynchronized relation to the movement of said conveying means, a crankpin carried by said member at a distance from the axis of rotation ofsaid member, a link having a slot extending in a direction endwisethereof, and fitting said pin so as to have a limited 10st motionconnection therewith, said link being connected at its other end to saidcradle at a distance from the axis of oscillation from said cradle, aspring acting upon said pin and urging it yieldingly against that end ofsaid slot which is nearest to the end connected to said cradle, wherebywhen said crank pin is returning said cradle to can-receiving position,it will do so through the action of said spring, a stop limiting themovement of said cradle in said returning direction to can-receivingposition and just before the maximum movement which would otherwise begiven said cradle by said crank pin, whereby said cradle will remainmomentarily stationary in can-receiving position While said springyields to movement of said pin along said slot until said link passesdead center position with respect to the axis of rotation of saidmember, and the pin returns along said slot until it again rigidlyengages said link and causes movement of said cradle in an invertingdirection, and means for receiving, and conveying away, a can invertedby said cradle.

10. In a machine for washing milk cans and the like, means for conveyingsaid cans positively in a prescribed path at definitely spaced intervalsand discharging them by a horizontal movement of the can, a cradledisposed in a position to receive a can discharged by said means throughsuch horizontal movement, said cradle being mounted for movement about asingle axis in a direction to fully invert the can so received, a memberrotating continuously and in synchronism with the movement of saidconveying means, and a crank and connecting rod connection between saidmember and said cradle and having dead center positions in can receivingand dis charging position of said cradle, whereby said cradle will bemoved to invert said cans by movement synchronized with respect to saidcan conveying means, and means for receiving and conveying away the cansinverted by said cradle.

11. In an upending mechanism for milk cans and the like, a segment of acylinder of sheet metal, an arcuate metal plate fitting the curvature ofsaid segment, and secured thereto and extending transversely thereof ata point approximately midway between its ends, bearing pins carried bythe ends of said plate and extending in directions transversely of thesegment and away from one another, bearing means for said pins with oneof the pins extending beyond its bearing, and an operating arm connectedto said extending pin at its free end.

JOHN P. MCIGNLEY.

